Gas-fired water heater



Sept 18, 1956 w. BRUMMERHOFF 2,763,244

GAS-NEED WATER HEATER Filed Oct. 4, 1951 mim" Fig. la

Wauw 45W# INVENTOR United States Patent O GAsfFrRED WATER-v HEATER Walter Brmmerhoft.RemseheidvLennep, Germany, as-

signor to Johann Vaillant Kommanditgesellschaft, Remscheid, Germany Application October 4^, 1951-, SerialgNo. 256,036 7 Claims# (Gllll-2451.2)

This invention4 relates to` gas-fired boiling-water heaters and. more particularly it has. reference, to water heaters employing the continuous 110W principleA for heating c old tapping Water to boiling temperature, as distinguished from hot-Watery heaters delivering hot but no boiling water.

Ordinary gaswater heaters for delivering boiling water heretofore in use have been of the open, pressureless type which are attended by the detrimental feature or" generarl ing a great deal of steam and requiring a relatively long starting up period till boiling watereen. be. withdrawn therefrom.,

The invention. isv based en: the discoveryA that it iS possible, under certain supnbsiousttQ-use. theA elosedteenstruetienY usually ehaileye-dy ier. hetrwaten heaters, alseto edventese. fer beilineewaten heaters instead of the4 open., pressureless Construction.. The term. closed. eonstnletion applies in tliepreseigit case tQ-such one which the water isf heated. by the. continuous. houx system, which is in. heat;- exeheiiee. with a heating ehemberue. lhe conmueve ow system can be formed, in a known manner, assnrple eine, coil, It.. however., water brought i0, boiling temperature in sneh a, oo ntinuous ilow system,` the; steam, forming inthe small-diameter pipesor; tubes, disturbs.v the how'. of water and. eausesinereased incrustetion.-Av

The, invention consists in preventingprejudical boiling et the water inthe closed continuous Howsystem,v byproviding a. spring-loaded pressure reliet valveon the servieeen d thereof. This will. cause that, depending upon the tensioni. of the spring, a, pressure apoye. atmbsllierie is built, up, in the` continuous; ilow. system, which pressure 11.0iwi-thSiemilifie` the heating ef. the water le nerfmel boil.- ing temperature prevents. its. boiling in` the. Coil.4 Hence, the. veler dees, het boil until it. is: relieved4 of. the. Pressure after its discharge from the heater; This pressure is so adjusted. that boiling water; can. still be, drawn also. under Unfavorable Service eondiibris Oi'. ses and weten ver: preventing boiling of the. Water in thepipe coil.

Unobjeotionable, i. e., trouble-.tree operat-ion, QE such a water heater depends. chiefly upon suitable Constr t'on oli the pressure, reliei valve.` The reliefg` valve; must` aet in suchfa manner that a certain quantity oii water, whieh is requisite for. obtaining; water of boi/1ine temp l thev service-.end i. the heater, can new olii: et the eentinuous how system. at, andL` above a. certa pressure only. As long as this pressure is not extant; erelief Valve must be keptA in closed, pe tion,` so that: the; heater, owing to the reaeibii 0i" the, Se-eelled weten defieieney Safety' device (which autom. ally' shins olif the, gas there is not enough water howling through the system)V will not be put in operation. Yet, upon a slight exceeding oi the lfellile Els'elliis the relief valve, must respond at once andi release a; large passage; area, so. as tov prevent shatteringA Off the valve body, and also for such reasons as to pre- Vtll't, that; there. is no. substantially higher pressure extant in'. the: heater than that required for boiling water delivery the heater is operated as hot-water heater. Further re- 2,763,244 Patented Sept. 18,1956

2 quirements are that ther relief'yalve is not susceptible to (or protected against) incrustation o fthe valve seat.-

It is therefore an object of the invention to provideV in a continuous-how Water heater a reliefV valve which` will fuliill these requirements and which is otherwise well adapted for the purpose for whichl the same is intended,

lt is known that an after-heating of the fluid talges place, which is still within the pipe coil, when any continuous How heater is shut-oit, because the fluid takes up the heat which is.` yet storedin the heat-exchanger. This after-heating, which means a heat. loss which should n ot be disregarded, is of great disadvantageA particularly in boiling-water heaters, which` according to the invention Operate bythe continuous.ilewprineiple;beeaus heated water, resting inthe coil', willv be the increase in incrustation.

It` is therefore. en importaitv object of` the invention. to overcome these disadvantages of such after-heating by prouidina a. tapping valye, ef. staeeiel. ferm Whieh iter.- tieulerlv suitable for the end. inview. Namely, the valve is so formed that, in the, course of closing-shortly beforeI it is fully clpsedfa: transitory increase in passage areaA takesplace. Consequently, thehot water, still in the coil after the water deficiency safety device has been shut off, will be pushed out of the heater, shortly before the valve is fully closed, by an additional quantity of Water which is fed intothc coil, so-that,`after the water has; been shut oit completely, the water remaining in the heater` at first is almost cold, and it isj not brought any more to the critical temperature at which the precipitation` ot scale begins by this afterheating These and other objects. and` advantagesof the invention will more fully appear from, the following description made in connection with.v theV accompanying drawings in which one embodiment of the invention is illustrated diagrammatically by Way of example.

In said drawings; v

Fig. l illustratesy the boiling-water heater according to the invention in partiallysectioned elevation, showing the essential parts ofthe invention o n a larger scale,V

Fig. la. is a plan of the iinnedv heating element, and

Fig. 2 illustrates another form of the tapping valve in side sectional elevation,

Disposed above a gas burner 1 is a ue 2, which is closed'at the top by means, of a finned heating element-3. A water-carryingvpipe coil. 4 is` wound around the outside wall of the. flue 2 several times and also passes through thenned heating element 3 several times.

The startingend of the coil 4:is connected to the housng- 5l of a hand operated tapping device 6. Supported infthe valve housing 5 is; a valve spindle 7 by means of which a valve member Si can be set as to the Valve seat 9. Another valve member 1Y0, which is provided with a spacing pin 10', is urged intoabutting engagement with. the valve spindle 7 by means ofau spring 11. When the valve 8 is open, the auxiliary-valve member 10 is spring-urged upon its seat 1g'. The cold-Water supply pipe 13. is connected to the pipe connection 13 on the valve housing 5. A duet 14 communicates upstream of the auxiliary valve 10, 12 with the cold Water supply pipe 13, whereas another waterV duct 15: establishes communication betweenl a pointl between the valve seats 9, and 12 and the supply pipe 13., A throttle member 17, which is under the. compression of spring 1.6 is; disposed within the water duct 15 and, by its position, determines the quantity of water flowing through the duct.

A throttle member or ilow restrictor l is mounted within, the `Sie,Hina-endl of the pipe Coil lu A pipe 1.9 leading t0 the chamber 2.0. ef a diaphragm Casina 2.1, branches. @if upstream of the throttle member 18- The lever diaphragm ehambei: ,2.0. is separated by 'rubati-sY et a rubber diaphragm from the upper diaphragm chamber 23, which is in communication with the coil 4 by means of a pipe 24 connected to the coil downstream of the throttle member or iiow restrictor 18. The diaphragm 22 controls a gas valve 26,disposed in the gas supply pipe 25 for the burner 1, in a known manner as water deficiency safety device.

The service-end of the coil 4 is connected to the housing 27 of a relief valve. There is a projecting valve seat on the bottom of the housing upon which the valve head 29 is seated. The valve head 29 is by means of a screw 30 connected to a metal diaphragm 31 which closes the valve chamber. The diaphragm 31 is stressed downwardly by a compression spring 32 which on its one end is seated upon a shoulder on the screw 30 and on its other end upon the cap 34 having a vent hole 33. The head of the screw 39 can abut the cap 34 and thereby limit the travel of the diaphragm 31 in such a manner that the diaphragm 31 can unseat the valve head 29 a sufiiciently great distance from its seat.

The principle of operation of the described boilingwater heater is the following: when the tapping valve 6 is open the cold water ows through the duct via the valve 8 to the coil 4. The throttle member 17 permits only a certain quantity of water to pass through which is determined by the compression of the spring 16. lf, due to increased pressure, cold water ow is increased more than desired, the throttle member is raised accordingly thereby reducing the passage area. The throttle `member 17 in conjunction with the spring 16 acts therefore as simple water-quantity regulator.

As soon as a certain quantity of water ows a pressure difference is formed across the throttle member 18 and consequently also in the diaphragm chambers 20, 23, and the gas valve 26 is opened and kept open by means of this pressure difference. However, the water can only flow and in turn actuate the water deficiency safety device if there is a water pressure which is great enough to open the relief valve 28, 29 on the discharge end.

The water flowing through the coil 4 s, during its passage therethrough, heated to atmospheric boiling temperature by the gas burned in the burner 1. However, it does not boil and no steam is formed yet because it is kept in the closed coil 4 under pressure above atmospheric by means of the valve 28, 29. TheV waterdoes boil and vaporize only after it has passed the relief valve 28, 29 and flows o.

The pressure acts upon the metal diaphragm 31, then overcomes the compression of the Ispring 32 and opens the valve 28, 29. After the valve 28, 29 has been opened, the effective area -of pressure on diaphragm 31 is increased by an area of approximately the cross-sectional area of the valve opening 28, sothat a lesser pressure is required to keep the valve open than that for opening it. Consequently, the valve 28, 29 once it is open cannot immediately be closed again when there is an insignificant reduction in pressure, so that chattering of the valve 29 cannot occur. In order to make the increase in effective area of pressure sufficiently large for all instances, the perimeter of the valve seat 28 is proportioned relatively large as compared with the free passage area so that the valve head 29 is seated upon a relatively wide valve seat.

As the hand operated tapping device 6 is closed the water passage between seat 9 and valve head 8 is continually decreased. But before the flow of water is shut off between 8, 9, the valve spindle 7 lifts the auxiliary valve from its seat 12, so that in this intermediate posi tion an additional quantity of water can flow in through the duct 14 by by-passing of the duct 15. The hot water yet remaining in the coil 4 is pushed out by this additional quanity of water, so that at the precise moment as the water supply is shut off completely-hence when the water deficiency safety device 26 is actuated in the sense of closingthe coil 4 is filled only with water which is almost cold. The heat stored in the finned heating element 3 and ue 2 is now transferred to the cold water. However, by this afterheating, the water is not brought anymore to the critical temperature in which precipitation of scale or incrustation begins.

Instead of the hand operated tapping device 6 there might be one installed having the form as shown in Fig. 2. In this valve provision is made for a relieved valve seat 36 in the valve housing 35 upon which a valve head 38 can be seated by means of afvalve spindle 37. The valve head 38 is provided with a throttle member 40 having a contracted neck 39. The position of valve head 38 and throttle member 40 in open position of the valve is indicated by dotted lines. As this tapping valve is closed, the throttle member 40, first of all, enters the valve seat 36 and shuts the water supply almost completely off, so that the water deficiency Isafety device 26 is actuated in the sense of closing. But as soon as, upon further closing of the tapping valve, the throttle member 40 has passed through the valve seat 36 and the contracted neck 39 is within the valve seat 36, the quantity of water owing through is transitorily increased, so that a certain quantity of cold water flows again into the coil 4, after the burner 1 is shut olf, and takes up the after-heat. During this brief subsequent inow of cold water, the water deficiency safety device 26, due to its inertia, is not actuated. Not till then the tapping valve is completely shut off by means of seating the valve head 38 upon the valve seat 36.

What is claimed is:

1. A gas heated continuous ow heater consisting of a gas burner, a flue for taking up the heating gases arranged above said burner, a closed pipe system, a cold-water supply pipe connected to said closed pipe system, means for transferring heat of said gas burner to said closed pipe system, a hand operated valve for controlling the quantity of water flowing through said closed pipe system, and means for transitorily increasing the passage area of said hand-operated valve during its closing movement before it is fully closed.

2. A gas heated continuous flow heater, consisting of a gas burner, a ue for taking up the heating gases arranged above said burner, a closed pipe system, a coldwater supply pipe connected to said closed pipe system, means for transferring heat of said gas burner to said closed pipe system, a hand operated tapping device for controlling the quantity of water flowing through said closed pipe system, said tapping device having a main valve and an auxiliary valve and means for operating both valves simultaneously, a main water duct controlled by said main valve and a by-pass arranged in parallel to said main water duct, said auxiliary valve being opened by said main valve and opening said by-pass before said main valve closes said main water duct.

3. A gas heated continuous flow heater, consisting of a gas burner, a ue for taking up the heating gases arranged above said burner, a closed pipe system, a coldwater supply pipe connected to said closed pipe system, means for transferring heat of said gas burner to said closed pipe system, a hand operated tapping device for controlling the quantity of water owing through said closed pipe system, said tapping device having a main valve and an auxiliary valve and means for operating both valves simultaneously, a main water duct controlled by said main valve, a throttling device in said main water duct for setting the main quantity of water, and a by-pass arranged in parallel to said main water duct, said auxiliary valve being opened by said main valve and opening said bypass before said main valve closes said main water duct.

4. A gas heated water heater according to claim 6, said tapping valve having a main valve and an auxiliary valve and means for operating both valves simultaneously, a main Water duct controlled by said main valve and a by-pass arranged in parallel to said main water duct, said auxiliary valve being opened by said main valve and opening said by-pass before said main valve closes said main water duct.

5. A gas heated continuous flow heater consisting of a gas burner, a ue for taking up the heating gases arranged above the burner, a closed pipe system, a cold water supply pipe, connected to said closed pipe system, means for transferring heat of the burner to said closed pipe system, a valve member for controlling the quantity of water owing through said closed pipe system, said valve member being axially movable by means of a spindle, an annular valve seat for said valve member, a throttle member provided with a contracted neck fastened to said valve member and said throttle member passing through said valve seat during the closing movement of said valve member.

6. A gas heated water heater consisting of a gas burner; a flue for taking up the heating gases arranged above said burner; a closed pipe system; a cold water supply connected to said closed pipe system; means for transferring heat of said gas burner to said closed pipe system; a hand operated tapping device at the feed intake of the closed pipe system for controlling the quantity of water flowing through said pipe system; a valve housing connected to the discharge end of said closed pipe system; a spring loaded diaphragm arranged in said valve housing; an outlet in said valve housing; and a valve body secured to said diaphragm in such a manner that the temperature of the water reaches the atmosphere boiling point without vaporization and which opens said outlet when a certain pressure lin the closed pipe system is exceeded.

7. A gas heated water heater consisiting of a gas burner;

a Hue for taking up the heating gases arranged above the burner; a closed pipe system; a cold water supply pipe connected to said closed pipe system; means for transferring heat of the burner to said closed pipe system; a hand operated valve at the feed intake of the closed pipe system for controlling the quantity of water owing through said closed pipe system; and a spring loaded pressure relief valve closing the discharge end of said closed pipe system in such a manner that the temperature of the water reaches the atmospheric boiling point without vaporization, said relief valve being adjusted to open automatically under the influence of a set maximum water pressure in the closed pipe system.

References Cited in the file of this patent UNITED STATES PATENTS 409,056 Moore Aug. 13, 1889 751,096 Netherg Feb. 2, 1904 1,583,557 Josse May 4, 1926 1,801,295 Warner Apr. 21, 1931 1,830,005 Sloan Nov. 3, 1931 1,883,733 Hahn Oct. 18, 1932 2,028,504 Eglotf Jan. 21, 1936 2,274,017 Weber Feb. 24, 1942 2,297,203 Decker Sept. 29, 1942 2,527,539 Frisch Oct. 3l, 1950 FOREIGN PATENTS 725,989 France May 20, 1932 316,499 Italy Apr. 9, 1934 

